Method and apparatus for immobilizing a patient and conducting an x-ray examination

ABSTRACT

Patient immobilizing apparatus comprises a patient supporting table unit on which a patient lies. The patient is covered by an imperforate sheet of film-like material which forms a seal between the patient&#39;&#39;s body and the table. The region between the table top, the patient and the sheet is evacuated so that differential pressure forces secure the patient on the table.

United States Patent 1191' Kliever 1451 Jan. 8, 1974 METHOD AND APPARATUS FOR IMMOBILIZING A PATIENT AND CONDUCTING AN X-RAY EXAMINATION [76] Inventor: Waldo H. Kliever, PO. 'Box 136,

Gates Mill, Ohio 44040 [22] Filed: Feb. 1, 1971 [21] Appl. No.: 111,602

[52] US. Cl 128/134, 250/491, 269/328 51 1111. C1 A6lg 13/00 [58] Field of Search ..269/323326,

[56] References Cited UNITED STATES PATENTS 3,286,693 11/1966 Clark, Jr. et a1 128/90 3,523,561 8/1970 Galeazzi 128/204 2,563,501 8/1951 Sperling 128/134 FOREIGN PATENTS OR APPLICATIONS 1,278,001 10/1961 France 128/204 Primary ExaminerWilliam E. Kamm AttorneyWatts, Hoffmann, Fisher & Heinke [5 7] ABSTRACT Patient immobilizing apparatus comprises a patient supporting table unit on which a patient lies. The patient is covered by an imperforate sheet of film-like material which forms a seal between the patients body and the table. The region between the table top, the patient and the sheet is evacuated so that differential pressure forces secure the patient on the table.

21 Claims, 13 Drawing Figures PAIENTEUJAN 83974 SHEET 2 0F 3 INVENTOR. WA 1.00 H. KLIEVER A TTOPNEY5 PATENTED 81974 SHEET 3 OF 3 WALDO H. KL/EVER R 0 T m m A TTORNE Y5 METHOD AND APPARATUS FOR IMMOBILIZING A PATIENT AND CONDUCTING AN X-RAY EXAMINATION BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to immobilization of patients for medical procedures and more particularly relates to a method and apparatus for immobilizing a patient undergoing X-ray treatment, or a child undergoing examination requiring restraint of the child.

The Prior Art It is sometimes desirable to position patients in various orientations during medical or X-ray procedures such as diagnostic or therapeutic X-ray treatment. In such circumstances movement of the patient to a particular orientation is required to allow accurate control of the direction of radiation passing through the body. Accordingly, patient supporting X-ray tables were designed to enable wide latitude in movement of the patient's body. The prior art has also proposed various other types of patient supports such as chairs, beds and examining tables which are provided with patient restraining apparatuses. These patient restraining apparatuses have generally includedstraps or harness-like arrangements which have been a source of discomfort to patients.

The means by which patients were secured to various patient supports and particularly manipulable'X-ray tables was not, in some circumstances, completely acceptable. The general requirements for a practicable patient restraining apparatus are as follows: l the patients body should be secured to the table for support in any orientation ofthe table; (2) the support should be comfortable without any high unit pressures such as might be caused by narrow straps, clamps,etc; (3) the apparatus should be universally applicable to patients regardless of their physical size, etc;-(4) the table and patient restraining apparatus should be designed for minimum obstruction to the radiation; (5) holding forces applied to the patients body should be applied and released without long delays and without disturbing suddeness; (6) the patient restraining apparatus should also be effective to restrain volitional movements of patients such as restraining infants fromundesired limb movements.

Additionally, any patient restraining or immobilizing apparatus should be safe, simple, inexpensive and reliable in operation. The prior art failed to propose X-ray tables and/or patient restraining apparatuses which satisfied the above enumerated requirements as well as being practicable.

SUMMARY OF THE INVENTION The present invention provides a new and improved patient immobilizing apparatus which is effective to maintain a patient firmly secured on a supporting device regardless of the orientation of the device. The new apparatus causes no discomfort because only small unit pressure forces are exerted on the patient. The new patient immobilizer is universally applicable to all patients and does not obstruct radiation directed to the patient. The invention is also effective in'restraining undesired volitional arm or leg movements.

According to the invention, the patient is restrained by the application of pressure forces. In a preferred embodiment of the invention, a patient supporting, manipulable X-ray table is provided with a patient supporting table top. A seal extends between the patients body and the table top and a pressure differential is established across the patient urging the patient against the table.

The region between the patients body, the seal and the table top is preferably evacuated by a suitable vacuum pumping system. The table top is constructed to enable distribution of vacuum pressure uniformly beneath the patient. In one preferred construction. the table top contains a vacuum manifold and a large num' ber of ports communicate the manifold with the region beneath the patient and the seal. The pressure forces acting on the patient are thus distributed uniformly over the patients body and unit pressure forces acting on the patients body are uniformly low. In this fashion relatively large total forces can be applied to patients for maintaining them in position on the table top without creating patient discomfort.

In the preferred embodiment of the invention, the seal is a film-like plastic sheet which is draped over the patient to cover the patient and the table top. The edges of the sheet are sealed to the table so that leakage of air at atmospheric pressure into the evacuated region is prevented. The plastic material need not be structurally strong since the pressure forces are respon sible for the patient support. In one experimentally operated patient immobilizer, sheets having 5-6 mil thicknesses were used in supporting an adult patient on an inverted table.

In some circumstances it may be necessary for a portion of the patients body to project from the sheet. For example, the patients head may not be covered by the sheet materiaLfurthermore, suturing, intravenous injections, etc., may be required while a patient is on the table. The sheet can be sealed about the patients neck, arms or legs by suitable tape and/or other sealing arrangements.

In another preferred embodiment of the invention the table top is constructed from a plurality of generally rectangular patient supporting land areas which are separated by narrow grooves. The patient supporting land areas project from the table top so that when a patient is supported on the table, the grooves communicate vacuum pressure to the region between the patients body and the table top.

' In still another embodiment, the table top is formed by a corrugated member having corrugations which extend along the length of the table. The corrugations form a plurality of ribs projecting from the table and which support the patient. The intervening grooves communicate vacuum pressure from one or both ends of the table to the region between the table top and the patient.

The restraining force applied to a patient can be controlled by a regulator valve which vents the vacuum system to atmosphere. This valve modulates the vacuum pressure to maintain a desired pressure-differential acting on the patient.

A device constructed according to the present invention is also effective for immobilizing a child preparatory to medical examination or treatment. It is frequently extremely difficult to restrain an uncooperative child. This is true not only for X-ray procedures but for otherunrelated procedures, such assuturing. The present invention provides quick and effective means for restraining the movements of such a child without harm or discomfort. I

A principal object of the present invention is the provision of a new and improved method and apparatus for restraining a patient for medical and/or X-ray procedures wherein the patient restraint is simple and effective yet does not cause patient discomfort and does not interfere with the medical treatment being administered.

Other objects and advantages of the present invention will become apparent from the following detailed description thereof made with reference to the accompanying drawings which form a part of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an X-ray table embodying the present invention and showing a patient supported on top of a generally horizontally extending table top;

FIG. 2 is a perspective view of the X-ray table shown in FIG. 1 but with the table top inverted so that the patient is facing downwardly;

FIG. 3 is a vertical cross sectional view seen from the plane indicated by the line 3 3 of FIG. 1;

FIG. 4 is a cross sectional view seen from the plane indicated by the line 44 of FIG. 3;

FIG. 5 is a fragmentary view similar to FIG. 3 and showing a sealing arrangement extending about the neck of a patient;

FIG. 6 is a fragmentary cross sectional view similar to FIG. 3 showing part of a table employing a foot rest;

FIG. 7 is a fragmentary cross sectional view ofa modified tabletop embodying the present invention;

' FIG. 8 is a fragmentary cross sectional view of another modified table top embodying the present invention;

FIG. 9 is a fragmentary cross sectional view of an edge of a table employing the table top structure illustrated in FIG. 8;

FIG. 10 is a fragmentary view seen generally from the plane indicated by the line 10-10 of FIG. 9;

FIG. 11 is a fragmentary cross sectional view ofa sealingarrangement for maintaining a sheet sealed to the edge of a table;

FIG. 12 is a modified sealing arrangement for main taining a sheet sealed against the table; and,

FIG. 13 is a fragmentary view of a sheet for covering a patients body and having a sleeve-like opening formed therein through which a portion of the body may extend during treatment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS An X-ray table unit 10 embodying the present inven tion is shown in FIGS. 1 and 2 of the drawings. The unit 10 includes support frames 12, 14 at opposite ends and a table assembly 16 suspended between the frames 12, 14. The table 16 supports a patient in position for exposure to X-rays or the like emanating from a source which is not shown.

The table assembly 16 supports the patient during examination and is manipulatable to enable positioning the patient in various orientations. The table 16 comprises a table base 18 connected to tubular rotatable support shafts 20, 22 which extend oppositely from the table end plates 24, 26 at respective ends of the base 18. The shafts 20, 22 connect the base 18 to the frames 12, 14 for rotation about a generally horizontal axis 27. The shafts 20, 22 are journalled to the respective frame members by bearing supports 28, 30.

A table top 36 is disposed over the table. base 18. The table top 36 provides a patient engaging surface. As is best seen in FIG. 4 both the base 18 and the table top 36 are generally cylindrically curved and are concave to conform to a patient lying on the table. Patient head and ankle rests 38, 40 respectively, are disposed on the table top.

- The patient is immobilized and maintained in position on the table assembly 16 by a new patient restraining system or apparatus (FIG. 1) embodying the present invention. The new restraining apparatus includes a system 46 for creating a pressure differential across the patients body and a seal sheet 47 between the patients body and the table top which enables the maintenance of the pressure differential at a desired level.

The system 46 is preferably a vacuum system which provides a subatmospheric pressure in the region between the patient, the seal and the tabletop 36. As is best illustrated in FIG. 1, the system 46 includes a suitable vacuum pump 48 which is preferably a motor driven blower unit which may be of any suitable or conventional construction.

The inlet of the pump 48 is connected to conduits 50, 52 (schematically indicated) which extend from the tubular support shafts 20, 22, respectively, to the blower inlet. The conduits 50, 52 open in the manifold 37 by way of passages 24a, 26a (FIG. 3) which formed in the end plates 24, 26, respectively.

Vacuum from the end plates is communicated to a chamber or manifold 54 defined between the table top 36 and the table base 18; The table top 36 includes a large number of ports 56 extending between the manifold 54 and the surface of the table top 36 on which the patient reclines. Accordingly, when the vacuum blower 48 is operated, the manifold 54 is evacuated and the pressure in the manifold is communicated to the patient engaging side of the table top 36 through the ports The pressure in the vacuum system 46 is modulated by a vacuum regulator valve which prevents system pressure from being reduced to a level which may cause patient discomfort. The regulating valve 57 communicates with the inlet of the pump 48 and the conduits 50, 52 and may be of any suitable conventional constructions. Typically a vacuum regulator valve of the type referred to employs a diaphragm operated valve member which admits controlled amounts of atmospheric air to the vacuum system when the vacuum pressure is reduced more thana desired level below atmospheric pressure. Generally the pressure in the manifold is maintained between about 0.5 psi and 1 psi below atmospheric pressure by the vacuum system. The vacuum regulator valve can be located on or adjacent the table so that any air at atmospheric pressure admitted by the valve flows across the patient and has a cooling effect due to evaporation of moisture from the patient as well as removing moisture.

The seal 47 extends between the patient and the table top so that the region between the seal, the patient and the table top can be maintained at subatmospheric pressure. The resultant differential pressure forces act on the patient to maintain the patient firmly positioned on the table. In the preferred embodiment, the seal 47 is an imperforate film-like sheet of plastic material such as polyvinylchloride (PVC) which is draped over the patient. The PVCsheet is preferably about 5 to 6 mils thick and need not be of great structural strength be cause the sheet itself does not support the patient. Furthermore, since the pressure differential across the sheet is relatively small the sheet will not rupture due to differential pressure forces.

Assuming an average patient body area of about 700 square inches, establishing a pressure differential of 1 psi across the patient will result in application of 700 pounds of restraining force on the patient. As noted, this force is applied uniformly across the patient and therefore does not cause discomfort as a result of localized high unit pressures. Maintenance of from 0.5 to l.() psi vacuum across an average adult patient enables the patient and table to be inverted (as seen in FIG. 2) safely and without discomfort caused by straps, etc., which would otherwise be necessary.

In the embodiment illustrated in FIGS. 1-3, the patients head and feet project from the sheet. Accordingly, the sheet is sealed about the patients neck and legs to prevent the entrance of air at atmospheric pressure into the region beneath the sheet. The seal can be formed by taping the edges of the sheet about the patients neck and legs. Depending on the treatment adthe patient must be accessible from outside the sheet. In such circumstances an access opening can be cut in the sheet and the boundary of the opening is taped to the patient around the location to which access is desired.

Although in the preferred embodiments of the invention the sheet 47 has been shown draped over the patient with the head and feet projecting from the sheet, the sheet could completely cover the patient so that the head and feet are located in the evacuated area beneath the sheet. An access opening could be formed in the sheet and taped in place to expose the patients face for breathing, etc. I

When'taping the sheet to the patient is undesirable or impractical, alternate sealing arrangements can be used. FIG. 5 shows a collar-like seal construction 62 between the patients neck and the sheet. The collar seal 62 includes a collar body 64 which supports a soft, resilient gasket 66 about the patients neck. The collar body 64 is preferably of a pliable substance to which the sheet 47 is adhered or otherwise detachably connected.

FIG. 6 shows a modification of the table of FIG. 3 in which a foot support 70 is connected to the table top and the patients feet are covered by the sheet 47. The foot support 70 is associated with suitable braces 73 which strengthen the foot support to enable the patient to be stood upright with the table. It should be appreciated that the patient is firmly maintained against the table top by the pressure differential established across the patients body. The foot rest member serves primarily to diminish the chances that the patient might slide downwardly along the upright table. The amount of patient weight borne by the foot support 70 for any given vacuum pressure'in the manifold 54 is dependent upon the coefficient of friction between the table top and the patient. This coefficient of friction is usually high enough that the weight borne by the foot support is small.

ministered, there may be occasions when locations on I As is seen in FIG. 4, the sheet can be attached to the bottom of the table base 18 by strips of tape 74 which extend along the edges of the sheet. The sheet tends to be self-sealing because the atmospheric air pressure urges the sheet against the table; however taping the edges to the table base insures against atmospheric air leaking into the evacuated area.

Instead of taping the cover in place, the cover can be formed by a sleeve of the PVC or equivalent material which extends completely about the table and is sealed to'the table at its ends. The sleeve can be provided with a zipper for enabling installation and removal.

. It has been found that cushioning certain portions of the patients body is sometimes desirable to prevent localized discomfort caused by pressure forces. For example, placing cushions behind the knees and ankles, as is shown in FIG. 3, minimizes discomfort which might otherwise occur as these joints are urged toward engagement with the table top by the differential pressure forces acting on them. The discomfort arises from straining the joint rather than from localized forces. Cushioning can also be employed where a patient has been injured and the additional differential pressure force acting on the patient might otherwise aggravate the injury or cause additional pain.

A portion of a modified table top 75 is illustrated in FIG. 7. The table top 75 is longitudinally corrugated and defines longitudinal ribs 76 and grooves 77. The ribs 76 are of generally rectangular cross sectional shape and adjacent ribs are separated by the grooves 77. The bases of the grooves 77 may engage the table body to support the table top. The patient reclining on the table top 75 is supported by the upper'faces 76a of the ribs 76. The vacuum system evacuates the grooves 77which are bridged by the patients body.

Another modified table top 80 is illustrated in FIG. 8. The table top 80 is defined by a mat-like base 81 having projecting lands 82. The lands are preferably of rectangular block-like form separated by grooves or recessed table top areas extending longitudinally and transversely along the base. When a patient is supported on the lands 82 the vacuum system evacuates the grooves or recesses 84. The table top of FIG. 8 is shown as a one-piece molded member; however the lands 82 can be constructed from blocks or porous rigid foam-like material adhered to the base 81. When so constructed, the effective area of the patients body across which the pressure differential acts is increased due to the porous character of the blocks. The restraining force acting on the patient is thus maximized for anygiven pressure in the vacuum system.

FIG. 9 shows a table employing the table top 80 associated with structure for maintaining the edges of the sheet 47 attached to the underside of the table. As is illustrated in FIGS. 9 and 10 the sheet edges are wrapped around the side of the table. A plastic hold down member 88 extends along theunderside of the table body at both sides. The member 88 carries a plurality of lands 90 which project downwardly from the table body and provide passages which communicate the vacuum pressure from the upper side of the table body to the vicinity of the free edge of the sheet. This provides for a differential pressure force acting on the sheet edges to maintain the sheet engaged with the table. The sheet is thus sealed in place and atmospheric air does not enter the evacuated area beneath the sheet.

Alternate constructions for maintaining the sheet in position at the edge of the table are shown in FIGS. 11 and 12. FIG. 11 shows a side seal member 92 which extends along the side of the table base 18 and which includes spaced lips 94, '6 which when slid over the sides of the table resiliently spread so that the sheet 47 is secured to the table body by the lips.

The side seal 100 illustrated in FIG. 12 defines lips 102, 104 which are spread and resiliently clamp the table edge when the side seal 100 is'in place. The sheet 47 extends around the outside of the seal 100 and the edge of the sheet is preferably held between the lip 104 and the lower side of the table base.

In some circumstances, it may be necessary for an arm or a leg to extend from the sheet 47. FIG. 13 illustrates a portion ofa sheet 47 having a sleeve-like structure 110 formed in it. The sleeve size and location is appropriate for an arm or leg to extend through it and the sleeve 110 can be taped in place so that aseal is maintained between atmospheric air and the arm or leg.

It can now be seen that a new and improved apparatus has been provided and that the objects heretofore enumerated and others have been accomplished. While preferred embodiments of the invention have been illustrated and described in detail, the invention is not to be considered limited to the precise constructions shown. It is the intention to cover hereby all adaptations, modifications and uses of the invention which come within the scope of the appended claims.

What is claimed is: I

l. A patient immobilizing apparatus comprising:

a; a patient supporting structure;

b. seal means comprising thin flexible sheet material adapted to extend over at least part of a patient, and having a substantially imperforate portion extending peripherally from said supporting structure to engage at least part of a patient to define a region between said patient supporting structure, the patient and said sheet material which is sealed from the atmosphere surrounding said apparatus;

c. connecting means for detachably connecting said sheet material to said patient supporting structure;

and,

d. pressure differential creating means for establishing a differential pressure between the atmosphere surrounding the apparatus and said region for creating a differential pressure force exerted on said at least part of a patient and said seal means for urging the patient toward said patient supporting structure.

2. A patient immobilizing apparatus as claimed in claim 1 wherein said pressure differential creating means comprises a vacuum system for evacuating said region.

'3. Apparatus as claimed in claim 2 wherein said vacuum system further includes valve means for controlling the level of differential pressure force acting on a patient.

4. Apparatus as claimed in claim 1 wherein said sheet material is comprised of plastic film.

5. Apparatus as claimed in claim 1 wherein said patient Supporting structure comprises a table unit, a table unit support and connecting means for connecting said table unit to said support structure for movement relative thereto to change the orientation ofa patient with said table.

6. Apparatus as claimed in claim 5 wherein said table unit comprises a patient engaging table top defining a plurality of paths by which fluid pressure is communicated to said region. 5 7. A method of immobilizing a patient comprising:

a. providing a patient support; b. placing a patient on said patient support; c. sealing a region between said patient support and a patient from the atmosphere surrounding the patient support and the patient;

d. evacuating said region to establish a pressure differential across the patient; and, e. maintaining a pressure differential across the pa- 5 tient to maintain the patient in position on said patient support.

8. The method claimed 'in claim 7 wherein sealing said region comprises covering a patient and at least part of said patient supporting member with a sheetlike seal member. I

9. A method of immobilizing a patient comprising:

a. positioning a patient on a patient supporting member;

b. forming a region between said patient supporting member and the patient which is isolated from the atmosphere ambient the patient and patient supporting member;

c. establishing a pressure differential across the patient to urge the patient toward said patient supporting member by reducing the pressure in said region below the pressure of the ambient atmosphere; and,

d. maintaining said pressure differential across the patient to immobilize at least part of the patient by application of differential pressure force to the patient.

10. The method claimed in claim 9 further including distributing differential pressure forces substantially uniformly over the patient.

1 1. The method claimed in claim 9 wherein establishing a pressure differential comprises establishing a subatmospheric pressure in said region on one side of the patient and exposing the opposite side of the patient to air at atmospheric pressure.

12. The method claimed in claim 11 further including controlling the subatmospheric pressure to control the differential pressure force acting on the patient.

13. In combination with an x-ray table comprising a table unit support, a table unit supported by said support and means cooperating with said table unit and said support for enabling movement of said table unit with respect to said table unit support to alter the orientation of a patient with said table, a patient restraining apparatus comprising:

a. a patient engaging table member;

b. seal means extending from the table member peripherally to engage at least part of a patient to define a region between at least part of a patient, the table member and said seal means which is sealed from the atmosphere surrounding the apparatus; and,

c. a vacuum system means communicating with said region for evacuating said region to create a differential pressure force acting on a patient to urge a patient toward said table member.

14. The combination claimed in claim 13 wherein said table member comprises a plurality of passages communicating said region' to said vacuum system means.

15. The combination claimed in claim 14 wherein said table member comprises a plurality of projecting lands for engaging a patient and wherein said passages extend between said lands; I

17. The combination claimed in claim 14 wherein said table member defines at least part of a manifold communicating with' 'said vacuum system means and said' passages are defined by openings extending be tween said manifold and said region.

18. A method of conducting an x-ray examination of a patient on a patient'support comprising: 7 v

a. positioning a patient with respect to the patient g support; g b. covering at least a portion of the patient with a sheet of a material which is substantially impermeable to air;

c. effecting a seal with said sheet to establish an evacuatable region between the patient, the sheet and the support;

d. establishing a pressure differential between ambient atmosphere and said region by partially evacuating the region and thereby urging the patient against the support; and,

e. conducting an x-ray examination while the pressure difi'erential is maintained.

19. The method of claim 18 further including the step of moving the support while the pressure differential is maintained and urging the patient againstthe. support to facilitate the examination.

20. The method of claim l9wherein the step of moving the support comprises rotating the support about an axis longitudinal of the patient.

21. The method of claim 19 wherein the step of moi) ing thesupport comprises tilting the'support from a position wherein the patient is prone. 

1. A patient immobilizing apparatus comprising: a. a patient supporting structure; b. seal means comprising thin flexible sheet material adapted to extend over at least part of a patient, and having a substantially imperforate portion extending peripherally from said supporting structure to engage at least part of a patient to define a region between said patient supporting structure, the patient and said sheet material which is sealed from the atmosphere surrounding said apparatus; c. connecting means for detachably connecting said sheet material to said patient supporting structure; and, d. pressure differential creating means for establishing a differential pressure between the atmosphere surrounding the apparatus and said region for creating a differential pressure force exerted on said at least part of a patient and said seal means for urging the patient toward said patient supporting structure.
 2. A patient immobilizing apparatus as claimed in claim 1 wherein said pressure differential creating means comprises a vacuum system for evacuating said region.
 3. Apparatus as claimed in claim 2 wherein said vacuum system further includes valve means for controlling the level of differential pressure force acting on a patient.
 4. Apparatus as claimed in claim 1 Wherein said sheet material is comprised of plastic film.
 5. Apparatus as claimed in claim 1 wherein said patient supporting structure comprises a table unit, a table unit support and connecting means for connecting said table unit to said support structure for movement relative thereto to change the orientation of a patient with said table.
 6. Apparatus as claimed in claim 5 wherein said table unit comprises a patient engaging table top defining a plurality of paths by which fluid pressure is communicated to said region.
 7. A method of immobilizing a patient comprising: a. providing a patient support; b. placing a patient on said patient support; c. sealing a region between said patient support and a patient from the atmosphere surrounding the patient support and the patient; d. evacuating said region to establish a pressure differential across the patient; and, e. maintaining a pressure differential across the patient to maintain the patient in position on said patient support.
 8. The method claimed in claim 7 wherein sealing said region comprises covering a patient and at least part of said patient supporting member with a sheet-like seal member.
 9. A method of immobilizing a patient comprising: a. positioning a patient on a patient supporting member; b. forming a region between said patient supporting member and the patient which is isolated from the atmosphere ambient the patient and patient supporting member; c. establishing a pressure differential across the patient to urge the patient toward said patient supporting member by reducing the pressure in said region below the pressure of the ambient atmosphere; and, d. maintaining said pressure differential across the patient to immobilize at least part of the patient by application of differential pressure force to the patient.
 10. The method claimed in claim 9 further including distributing differential pressure forces substantially uniformly over the patient.
 11. The method claimed in claim 9 wherein establishing a pressure differential comprises establishing a subatmospheric pressure in said region on one side of the patient and exposing the opposite side of the patient to air at atmospheric pressure.
 12. The method claimed in claim 11 further including controlling the subatmospheric pressure to control the differential pressure force acting on the patient.
 13. In combination with an x-ray table comprising a table unit support, a table unit supported by said support and means cooperating with said table unit and said support for enabling movement of said table unit with respect to said table unit support to alter the orientation of a patient with said table, a patient restraining apparatus comprising: a. a patient engaging table member; b. seal means extending from the table member peripherally to engage at least part of a patient to define a region between at least part of a patient, the table member and said seal means which is sealed from the atmosphere surrounding the apparatus; and, c. a vacuum system means communicating with said region for evacuating said region to create a differential pressure force acting on a patient to urge a patient toward said table member.
 14. The combination claimed in claim 13 wherein said table member comprises a plurality of passages communicating said region to said vacuum system means.
 15. The combination claimed in claim 14 wherein said table member comprises corrugations defining longitudinally extending ribs for engaging a patient and wherein said passages are defined by grooves between said ribs.
 16. The combination claimed in claim 14 wherein said table member comprises a plurality of projecting lands for engaging a patient and wherein said passages extend between said lands.
 17. The combination claimed in claim 14 wherein said table member defines at least part of a manifold communicating with said vacuum system means and said passages are defined by openings extending between said maNifold and said region.
 18. A method of conducting an x-ray examination of a patient on a patient support comprising: a. positioning a patient with respect to the patient support; b. covering at least a portion of the patient with a sheet of a material which is substantially impermeable to air; c. effecting a seal with said sheet to establish an evacuatable region between the patient, the sheet and the support; d. establishing a pressure differential between ambient atmosphere and said region by partially evacuating the region and thereby urging the patient against the support; and, e. conducting an x-ray examination while the pressure differential is maintained.
 19. The method of claim 18 further including the step of moving the support while the pressure differential is maintained and urging the patient against the support to facilitate the examination.
 20. The method of claim 19 wherein the step of moving the support comprises rotating the support about an axis longitudinal of the patient.
 21. The method of claim 19 wherein the step of moving the support comprises tilting the support from a position wherein the patient is prone. 